Thursday 12 June 2014

Light Exposes ‘Evil Twins’

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A combination of nanotechnology and a unique twisting property of light could lead to new methods for ensuring the purity and safety of pharmaceuticals. A direct relationship between the way that light is twisted by nanoscale structures, and the nonlinear way that it interacts with matter, could be used to ensure greater purity for pharmaceuticals, allowing for “evil twins” of drugs to be identified with much greater sensitivity. Researchers from the Univ. of Cambridge have used this relationship, in combination with powerful lasers and nanopatterned gold surfaces, to propose a sensing mechanism that could be used to identify the right-handed and left-handed versions of molecules. Some molecules are symmetrical, so their mirror image is an exact copy. However, most molecules in nature have a mirror image that differs — try putting a left-handed glove on to your right hand and you’ll see that your hands are not transposable one onto the other. Molecules whose mirror-images display this sort of “handedness” are known as chiral. The chirality of a molecule affects how it interacts with its surroundings, and different chiral forms of the same molecule can have completely different effects. Perhaps the best-known instance of this is Thalidomide, which was prescribed to pregnant

The post Light Exposes ‘Evil Twins’ has been published on Technology Org.

 
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Universities can’t fulfill the myth, but they can’t become vocational schools either

Science Focus

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Is it time to rethink higher education? I'm someone who went through the system and I'm now, to a greater or lesser extent, contributing to its maintenance, so it seems strange that I should advocate its dismantling. Yet I'm beginning to think that I ought to.

Unlike most rants of this nature, I have no complaints about the modern standard of education. The myth of falling standards has been with us since the Roman republic decided that they wanted the south of France as their personal back garden. If they really were falling for that long, we would all be living in caves wondering how our fore bearers were able to create this thing called fire.

Indeed, I think that students today learn a hell of a lot more than I did in my day. Although I may mourn the fact that Lagrangian mechanics is now a footnote on the way to a physics degree, that is not a sign of falling standards, but rather tells us that it is more important to learn other things to obtain a relevant education.

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 » see original post http://feeds.arstechnica.com/~r/arstechnica/science/~3/p6cBVDhwc_8/
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Light waves allow preferred bond breaking in symmetric molecules

Science Focus

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Figure 1: Illustration of the directional proton emission in acetylene with a specific laser waveform. The superposition of vibrational modes, which are responsible for the selective bond breaking, results from a combination of laser excitation of the anti-symmetric CH stretching mode and excitation of the symmetric CH stretching mode through ionization steps. The ionization steps are indicated by a change in colour from green (neutral) over yellow (cation) to orange (dication). Credit: Christian Hackenberger, MPQ, Attosecond Physics division An international team of scientists discovered a new quantum control mechanism to selectively shake and break C-H bonds in symmetric hydrocarbon molecules with the waveform of femtosecond laser pulses. Chemical bonds between carbon and hydrogen atoms are amongst the strongest in nature and their selective breaking, in particular in symmetric molecules, is of interest to chemical synthesis and the development of new biologically active molecules. An international team of scientists has now demonstrated that ultrashort light pulses with perfectly controlled waveforms can selectively break C-H bonds in acetylene ions. The researchers demonstrated that a suitable choice of the laser-pulse waveform leads to breaking of the C-H bond on the left (or right) side of the symmetric H-C≡C-H molecule. The scientists propose that

The post Light waves allow preferred bond breaking in symmetric molecules has been published on Technology Org.

 
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 » see original post http://feedproxy.google.com/~r/TechnologyOrgPhysicsNews/~3/MzCwgPiYKy0/
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VIDEO: Climate change to cause flash floods

Science Focus

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The Met Office has issued a warning of more summer flash floods, because of climate change. 
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 » see original post http://www.bbc.co.uk/news/science-environment-27658249#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa
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Mining data archives yields haul of 'red nuggets' galaxies

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The world of astronomy has changed. An astronomer used to have to travel to a remote location and endure long, cold nights, patiently guiding a telescope to collect precious photons of light. Now, a proliferation of online archives allows astronomers to make discoveries from the comfort of their own offices. By mining such archives, a team of astronomers has found a treasure trove of 'red nugget' galaxies.

via Science Daily

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Tadpole Nebula, Auriga Constellation Star Stickers

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Galaxies, Stars and Nebulae series An awesome outer space picture featuring the Tadpole Nebula, a star forming hub located about 12000 light years away in the Auriga constellation.
This nebula is brimming with new-born stars, many as young as only a million years of age. It's called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and130, the yellow forms that seem to be swimming away from the three red stars close to the centre of the picture.

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Image credit: NASA/JPL-Caltech/UCLA

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The Tarantula Zone

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The Tarantula Nebula is more than 1,000 light-years in diameter, a giant star forming region within our neighboring galaxy the Large Magellanic Cloud (LMC). That cosmic arachnid lies toward the upper left in this deep and colorful telescopic view made through broad-band and narrow-band filters. The image spans nearly 2 degrees (4 full moons) on the sky and covers a part of the LMC over 8,000 light-years across. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other violent star-forming regions with young star clusters, filaments, and bubble-shaped clouds In fact, the frame includes the site of the closest supernova in modern times, SN 1987A, just above center. The rich field of view is located in the southern constellation Dorado.

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Scientists demonstrate improved catalyst control, energy savings could result

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 Inspired by how enzymes work in nature’s biological processes, researchers have demonstrated a way to improve control of synthetic catalysts, according to a paper co-authored by a University of Alabama computational chemist that was published in a recent online issue of the journal Nature Nanotechnology. “This work is an exciting example of how we are learning to improve control of chemical reactions at the level of a single atom,” said Dr. David Dixon, the Robert Ramsay Chair of Chemistry at The University of Alabama. Catalysts accelerate chemical reactions so that they go faster and use less energy. Estimates indicate that the economic impact of catalytic processing, including pollution abatement, is \$10 trillion annually, Dixon said. The UA researcher cited improving the conversion of biomass – typically plant-based materials – into transportation fuels as an example of how designing more efficient catalysts could benefit society. The paper, titled “Selective molecular recognition by nanoscale environments in a supported iridium cluster catalyst,” was published in the journal’s online edition April 20. In the research, sponsored by the U.S. Department of Energy, the scientists showed how to switch molecular bonding – the interaction that holds assemblies of atoms together – off and on at will

The post Scientists demonstrate improved catalyst control, energy savings could result has been published on Technology Org.

 
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North American and Pelican Nebulae Stickers

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Galaxies, Stars and Nebulae series A gorgeous picture from outer space featuring the North American and Pelican emission nebulae in the constellation of Cygnus, The Swan. The red, green and yellow areas all highlight the cloud of interstellar ionised hydrogen.
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Image credit: NASA/JPL-Caltech

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